A fluid (e.g., Intravenous (IV) fluid, bladder irrigation fluid, etc.) is often delivered to a patient via a fluid supply reservoir (e.g., an IV administration set, such as a gravity-fed IV drip bag) or a fluid infusion pump (e.g., an IV pump). A gravity-fed fluid delivery system typically includes a drip chamber (also referred to as a reservoir) and flexible tubing through which the fluid is delivered to a patient. When the IV fluid container or bag is empty, the drip chamber will run dry and the fluid flow will eventually stop. A large number of gravity-fed fluid drip bags used in the operating room (OR) or hospital ward environment run dry before being changed. Many gravity-fed fluid drip bags run dry undetected during high stress procedures where multiple lines and bags are in use, as is typically the case during complex surgery, emergency response or in ambulances.
When a fluid bag runs dry the patient can be exposed to increased risks. These risks when receiving IV fluids include: complications of clotting and obstruction of the IV catheter; possible awareness under general anesthesia if the IV line is being used to administer total intravenous anesthetic; and venous air embolism when the IV fluid bag is pressurized for rapid infusion as is often the case during emergency situations. While automatic infusion pumps are used in standard care wards and areas of “routine” care, they are expensive and time-consuming to program and as such are unsuitable for use in trauma, surgical or emergency use. Similarly, when a bag delivering fluid to a patient receiving continuous bladder irrigation runs dry, the risk of bleed and requirement for further surgical intervention is high. As such, improved methods and devices for controlling the delivery of IV fluid to a patient would be beneficial.